Preservative for milk



UNITED" STATES PATENT; or'rlca.

GEORGE GRINDROD, OF KENT, WASHINGTON, ASSIGNOR TO OAR/NATION MILN PRODUCTS 00., OF SEATTLE, WASHINGTON, A CORPORATION OF MAINE PRESERYATIVE FOR MILK.

'80 Drawing.

To all whom it may concern."

Be it known that I, GEORGE Gnmnnon, a citizen of the United States, and residing in the city of Kent, county of King, and State of Washington, have invented certain novel Preservatives for Milk, of WhlCh the followin is a specification.

his invention relates to preservatives for milk, and more particularly has for its object to provide an efiicient preservative adapted-to be used for preserving the samples of fresh milk which are taken from the shipping cans when such milk is received at the condensation or evaporation plants. It is the practice in these plants, when the milk is received from the producers in various quantities, and as these quantities are emptied into a receiving vat, to take a sample from each container, which sample is labeled to correspond to the number of the container. By these sam les, a check is maintained upon the qua ity of the milk received. The samples are taken from day to day and placed in stoppered glass jars, a separate jaror bottle bein each producer or shipper. t intervals of about one week, the accumulated samples, each representing the milk received from one producer or shipper during that period of time, are analyzed or tested for butter fat, and the milk is paid for in accordance with these analyses or tests. Thus it will be understood that it is important to' preserve the samples in substantially the same condition in which the milk is received.

Heretofore, certain preservatives have been used for the purpose indicated above,

but all of them have proved unsatisfactory for some reason or other, and many efforts .have been made, so far unsuccessful, to provide an efiicient and satisfactory preservative for such samples of milk. The preservatives used hitherto have been unsatisfactory for one or more of the following reasons: I

( 1) Because they are not sufliciently powerful; (2) because (as in the case of formaldehyde) they were not stable or permanent, or lost their-strength after being put in the milk; (3) because (as in the case of bichromates) the interfered with the subsequent testing 0 the milk if used in quantities large enough to preserve the milk; (4;

because (as in the case of mercuric chlorid provided for Specification of Letters Patent. Patented Och 11, 1921. Application filed January 7, 1918. Serial No. 210,617. i

they were colorless, and, therefore, it was or not the sam le had been treated with the preservative; 5) because (as in the case of b chromates) they could not be made into a hquldstrong or dense enough to effect only a negligible dilution of the sample.

In order to satisfy all the requirements,a preservative for milk samples ought to be powerful enough to preserve a verylarge amount of milk, say up to twenty thousand times its own wei ht; the preservative ought to be entirely ,sta le, both while being held ready for use and while mixed with the sample 1t ought to give the milk a readily discernible permanent color; it should not interfere with the analyzing of the sample; and, lastly, it ought to be a liquid containmg only a very small and negligible amount of water.

As a result of numerous experiments and extensive research, I have succeeded in producing a novel preservative meeting all the requirements enumerated above and its superlority over preservatives employed'hitherto is particularly marked in this respect that, so far as I am aware, the new preservative. is the only one which can be prepared in liquid form of such density as to effect only a negligible dilution of the sample, and which at the same time, when used in such strength will not interfere with the subse quent testing of the milk. I

My improved preservative comprises a powerful, stable preservative dye in conjunction with a soluble mercur' salt. It has been found that mercuric ch orid when used alone is unsuitable, because it has no color, and, therefore, does not indicate at a glance that the milk in which it is used is poisonous. On the other hand, most dyes are insoluble or unstable in a concentrated solution of a mercury salt. I have found that fuchsin is a very powerful reservative in itself, but is insufficiently so uble except when used in the form of h drochlorid, that is to say, of an acid salt. he hydrochlorid is yellow, and thus has a less marked color than required when it is used as a preservative, but when added to the milk it becomes disassociated and the full color of fuchsin is restored. Fuchsin has a preserving power approximately the same as that of mercuric chlorid, both-being themost powerful pre- I HgCl a Cl.

servatives available hitherto.- The joint use of fuchsin and mercuric chlorid yields a liquid which can be easily measured and at the same time requires so little water as to cause no a preciable dilution of the milk sample. Tius from two to three drops added to the usual size of milk sample (12 ounces) will effect complete preservation. Neither element of the new preservative has any marked oxidizing power, and, unlike other preservatives, it does not interfere with the subse uent analysis or testing of the milk. Furt ier, both of the elements of the novel preservative or com ound separately and mixed are unaffecte by enzyms or other constituents of milk, remaining unchanged in the milk and retaining their full preserving power indefinitely, being in this respect superior to formaldehyde or other organic preservatives.

In carrying out the preferred form of my invention, mercuric chlorid HgCl is dis solved with sodium or any other alkali metal (K,Am.) chlorid and in this manner I obtain a double chlorid of mercury and of an alkali 7 metal, and' if sodiumwas used this double chlorid will have the formula Any one of these double chlorids is soluble in water to such an extent as to produce a solution containin more than one gram df mercuric chlorid (IIgCI per cubic centimeter. The mercuric chlorid is heated with the sodium chlorid in the presence of a suitable amount of water (say 25%) and then a solution of fuchsin hydrochlorid C H, N HCl, sufficient to make one per cent. of fuchsin in the finished product, is acidified with hydrochloric acid (HCl) and is then added to the mercury salt solution, whereupon the whole mass is diluted to the point where one cubic centimeter contains one gram of HgCl Thus, by the mixture or joint use of fuchsin and a mercury chlorid, a compound or substance is produced which is an admirable preservative for milk samples, and which does not affect the subsequent analysis of the milk; at the same time this substance preserves the milk, and by coloring the sample gives warning of the fact that the sample has been treated with a poisonous substance.

.lVhile I have described a preferred form of my invention, it is obvious that changes may be made therein, within the spirit and .scope thereof, as defined in the appended claims.

I claim:

1. A milk preservative solution consisting of a hydrochloric acid salt of fuchsin 'with an excess of hydrochloric acid, and a double chlorid df mercury and an alkali metal, in liquid state, said solution containing approximately one per cent. of fuchsin.

2. A milk preservative, consisting of a solution of a hydrochloric acid salt of fuchsin with an excess of hydrochloric acid, and a double chlorid of mercury and an alkali metal, said solution'having approximately one per cent. (1%) of fuchsin, containing approximately one gram of mercuric chlorid percubic centimeter.

'3. .A process of making a milk preservative which consists in heating a mercuric chlorid with sodium chlorid and the desired amount of water, then adding a solution of fuchsin hydrochlorid acidified with hydrochloric acid, sufficient to make approximately one per cent. offuchsin in the finished product, and then diluting the mixture to the point where one cubic centimeter contains one gram of mercuric chlorid.

4. A process of making a milk preservative, which consists in treating mercuric chlorid with a chlorid of alkali metal in the presence of water, then adding a solution of an acid salt of fuchsin having.an excessof hydrochloric acid, and then diluting the mixture until one cubic centimeter of the final product contains approximately one gram of mercuric chlorid.

,5. A process of making a milk preservative, which consists in treating mercuric chlorid with a chlorid of an alkali metal in the presence of water, then adding an amount of a solution of fuchsin hydrochlorid, acidified with hydrochloric acid, sufficient to make approximately one per cent. of fuchsin in the finished product, and then diluting the mixture to the'point where one cubic centimeter contains one gram of mercuric chlorid.

In testimony that I claim the foregoing as my invention, I have signed my name in the presence of two subscribing wltnesses.

GEORGE GRINDROD.

I Witnesses:

A. Y. COUGAN, H, N. STUART, 

